Papers by Hashim Said Ali
Journal of the Arkansas Academy of Science, 2015
Three seed types: bean (Phaseolus vulgaris), corn (Zea mays) and radish (Raphanus sativus) were f... more Three seed types: bean (Phaseolus vulgaris), corn (Zea mays) and radish (Raphanus sativus) were flown in a high altitude weather balloon into the midstratosphere to investigate the effects of high altitude radiation on germination success and seedling growth. After recovering and planting the seeds, the bean seeds showed lower germination success with exposure to high altitude radiation, and consequently stunted seedling growth. Corn and radish seeds experienced a statistically significant positive effect on germination success from radiation exposure compared to control seeds, but negative effect on seedling growth. Overall, the field experiments presented here support laboratory studies that show radiation exposure on vegetable seeds has a mixed effect on the germination success and negative effect on seedling growth on investigated seed types.
Swarm robotics is a new area of interest that’s inspired from biological system of ants, birds an... more Swarm robotics is a new area of interest that’s inspired from biological system of ants, birds and other social systems for solving different optimization problem. This paper work out to find the optimal path using particle swarm optimization algorithm and dijkstra’s algorithm, these algorithms are used to find the shortest path between different nodes. Different path can exist from one node to another node, particularly combinational optimization algorithm are used to solve such optimization problem. Different algorithms are used to solve the given problem. The PSO repeatedly find out the better solution for the given problem. The dijkstra’s algorithm used to check the convenience path between different nodes. Problem arise in PSO of flout delay cost at each node where the dijkstra’s keep the delay cost at each node with some specific value. Our current work propose the approach to merge the PSO and Dijkstra’s algorithm to provide new method of solving the optimization problem.) Ke...
Journal of Systems and Software, 2021
With rapid availability of renewable energy sources and growing interest in their use in the data... more With rapid availability of renewable energy sources and growing interest in their use in the datacenter industry presents opportunities for service providers to reduce their energy related costs, as well as, minimize the ecological impact of their infrastructure. However, renewables are largely intermittent and can, negatively affect users' applications and their performance, therefore, the profit of the service providers. Furthermore, services could be offered from those geographical locations where electricity is relatively cheaper than other locations; which may degrade the applications' performance and potentially increase users' costs. To ensure larger providers' profits and lower users' costs, certain non-interactive workloads could be either: moved and executed in geographical locations offering the lowest energy prices; or could be queued and delayed to execute later (in day or night time) when renewables, such as solar and wind energies, are at peak. However, these may have negative impacts on the energy consumption, workloads performance, and users' costs. Therefore, to ensure energy, performance and cost efficiencies, appropriate workload scheduling, placement, migration, and resource management techniques are required to mange the infrastructure resources, workloads, and energy sources. In this paper, we propose a workload placement and three different migration policies that maximize the providers' revenues, ensure the workload performance, reduce energy consumption, along with reducing ecological impacts and users' costs. Using real workload traces and electricity prices for several geographical locations and distributed, heterogeneous, datacenters, our experimental evaluation suggest that the proposed approaches could save significant amount of energy (∼15.26%), reduces service monetary costs (∼0.53%-∼19.66%), improves (∼1.58%) or, at least, maintains the expected level of applications' performance, and increases providers' revenue along with environmental sustainability, against the well-known first fit (FF), best fit (BF) heuristic algorithms, and other closest rivals.
Cardiovascular research, Jan 24, 2017
The Notch signaling pathway regulates the balance between proliferation and differentiation in se... more The Notch signaling pathway regulates the balance between proliferation and differentiation in several tissues, including the heart. Our previous work has demonstrated that the proliferative potential of neonatal cardiomyocytes relies on Notch1 activity. A deep investigation on the biochemical regulation of the Notch signaling in cardiomyocytes is the focus of the current research. We show that the Notch1 intracellular domain is acetylated in proliferating neonatal rat cardiomyocytes and that acetylation tightly controls the amplitude and duration of Notch signaling. We found that acetylation extends the half-life of the protein and enhanced its transcriptional activity, therefore counteracting apoptosis and sustaining cardiomyocyte proliferation. Sirt1 acted as a negative modulator of Notch1 signaling; its overexpression in cardiomyocytes reverted Notch acetylation and dampened its stability. A constitutively acetylated fusion protein between Notch1 and the acetyltransferase domain...
Reaction Kinetics, Mechanisms and Catalysis, 2015
Short path gas cell Fourier transform infrared spectroscopy was used to analyze the production of... more Short path gas cell Fourier transform infrared spectroscopy was used to analyze the production of hydrochloric acid (HCl) gas from the reaction of sodium chloride (NaCl) particles and sulfuric acid (H 2 SO 4) or nitric acid (HNO 3) at a range of relative humidity (2-95 %). HCl was produced from both acids, and reached equilibrium in 10 min for both H 2 SO 4 and HNO 3 acids. The equilibrium is thought to be a result of two competing reactions which produce HCl and sequester it back into the NaCl particles. The HCl production from H 2 SO 4 was instantaneous, but its production from HNO 3 involved an induction period of a few minutes. The equilibrium HCl conditions observed here have implications in influencing the pH of aerosol particles, and consequently the acidity of precipitation in the atmosphere.
EBioMedicine, 2017
Besides its essential role in the activation of HIV-1 gene expression, the viral Tat protein has ... more Besides its essential role in the activation of HIV-1 gene expression, the viral Tat protein has the unusual property of trafficking in and out of cells. In contrast to Tat internalization, the mechanism involved in extracellular Tat release has so far remained elusive. Here we show that Tat secretion occurs through a Golgi-independent pathway requiring binding of Tat with three short, non-consecutive intracytoplasmic loops at the C-terminus of the cellular Na(+),K(+)-ATPase pump alpha subunit. Ouabain, a pump inhibitor, blocked this interaction and prevented Tat secretion; virions produced in the presence of this drug were less infectious, consistent the capacity of virion-associated Tat to increase HIV-1 infectivity. Treatment of CD4+ T-cells with short peptides corresponding to the Tat-binding regions of the pump alpha subunit impaired extracellular Tat release and blocked HIV-1 replication. Thus, non canonical, extracellular Tat secretion is essential for viral infectivity.
Economic and Political Weekly, Nov 24, 1984
Composite sandwich structures have excellent properties and they are widely used in the fields of... more Composite sandwich structures have excellent properties and they are widely used in the fields of high technology such as aeronautics and astronautics, etc. Investigations of the mechanical properties of composite sandwich structures play a vital role in deciding their applicability in various engineering fields. After years of effort, along with several achievements, new difficulties have been encountered with the emergence of a lot of novel sandwich structures in recent years. The quasi-static indentation response, low-velocity impact response, residual strength after impact and high-velocity impact response of these structures has been investigated by theoretical, numerical and experimental methods. The mechanical behavior of sandwich structures is strongly dependent on the loading rate. In the case of static loading the structure have a ductile behavior, but in the case of impact loading it may behave in a brittle manner and fail catastrophically. The advances of the mechanical properties of foam sandwich composites are reviewed from several aspects, including the, low-velocity impact response, and the finite element model for low- velocity impact of composite sandwich structures.
VAWKUM Transactions on Computer Sciences, 2015
The popularity of java programming is growing continuously, as Java gives an independent, object ... more The popularity of java programming is growing continuously, as Java gives an independent, object oriented and multithreaded programming environment.[1] J2ME (Java 2 Micro Edition) is the Most Ubiquitous Application Platform for Mobile Devices and provides a robust flexible environment for all application running on cell phones and also other embedded devices[11][12]. In this paper an application is develop for mobile phone and PC (Personal Computer), using Java programming language. The main function of this application is to transfer images automatically from mobile phone to PC or laptop and also save these images in computer system memory (Hard Disk), whenever mobile phone detect PC or laptop in its Bluetooth range. The mobile phone app save the PC name in its database as server and sends the images to only that PC while the rest of the PC in its Bluetooth range are ignored plus the mobile app also save the sent images name list so that the images are not send twice to PC. This application has been tested on student's mobile phones in the university premises and shows a promising results and will also be tested on public mobile devices in future studies.
Saudi journal of kidney diseases and transplantation : an official publication of the Saudi Center for Organ Transplantation, Saudi Arabia, 2009
Almost all forms of glomerular diseases have been reported in diabetics. In a recent series, 12% ... more Almost all forms of glomerular diseases have been reported in diabetics. In a recent series, 12% of those with type I and 27% of those with type II diabetes were found to have non diabetic renal disease. We studied 80 adult diabetic Iraqi patients who were diagnosed with glomerular disease on native kidney biopsies from January 2000 to April 2008. Membranoproliferative GN was seen in 32 patients (40%), focal and segmental glomerulosclerosis in 16 patients (20%), membranous nephropathy in 20 patients (25%), minimal change disease in 8 patients (10%), renal amyloidosis in 4 patients (5%). In conclusion Membranoproliferative GN was the most common histological diagnosis in our diabetic patients undergoing renal biopsy.
Genetic Algorithm (GA) is a very useful tool to search and op timize many engineering and scienti... more Genetic Algorithm (GA) is a very useful tool to search and op timize many engineering and scientific problems. In this paper, a real tim e enhanced biomedical model of humanoid structure is developed in MSC visual Nastran to assist the paraplegic patient. The complexity of the m odel is driven by the needs that the model parameters must be estim ated for an eventual individual with disability. After the development of hum anoid structure an inverse model is designed to estim ate the joint torques. The re ference trajectories of the humanoid m odel are obtained from MSC visual Nastran.The controllers are des igned in M atlab/ Simulink for f our joints which are manually tuned simultaneously to obtain the results. Afterwards, GA is used to tune the P ID controllers to find the optimal solutions which are com pared with manually tuned PIDs. The re sults are shown and hence it is proved that GA has given a better optim ized control system.
2013 European Modelling Symposium, 2013
ABSTRACT Activity recognition systems have been found to be very effective for tracking users&... more ABSTRACT Activity recognition systems have been found to be very effective for tracking users' activities in research areas like healthcare and assisted living. Wearable accelerometers that can help in classifying Physical Activities (PA) have been made available by MEMS technology. State-of-the-art PA classification systems use threshold-based techniques and Machine Learning (ML) algorithms. Each PA may exhibit inter-subject and intra-subject variability which is a major drawback for threshold and machine learning based techniques. Due to lack of empirical data in order to train classifier for ML clustering algorithms, there is a need to develop a mechanism which requires less training data for PA clustering. This paper describes a novel personalized PA recognition model framework based on a semi-supervised clustering approach to avoid fixed threshold techniques and traditional clustering methods by using a single accelerometer. The proposed methodology requires limited amount of data to compute (initial) centroids for PA clusters and achieved an accuracy of about 93% on average, moreover it has the potential capability of recognizing subjects' behavioral shifts and exceptional events, falls, etc.
2009 2nd International Conference on Computer, Control and Communication, 2009
Ad hoc networks (MANET) frequently changing network topology using multi-hop wireless links witho... more Ad hoc networks (MANET) frequently changing network topology using multi-hop wireless links without existing network infrastructure. Anycast routing is important for Ad hoc network in terms of resource, robustness and efficiency when mobility is high and links get disconnected ...
Physical Chemistry Chemical Physics, 2005
The heterogeneous uptake and reactivity of formic acid (HCOOH), a common gas-phase organic acid f... more The heterogeneous uptake and reactivity of formic acid (HCOOH), a common gas-phase organic acid found in the environment, on calcium carbonate (CaCO 3) particles have been investigated using a Knudsen cell reactor, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). FTIR measurements show that the adsorption of formic acid on the surface of calcium carbonate results in the formation of calcium formate. Besides calcium formate, carbonic acid is also a reaction product under dry conditions (o1% RH). Under dry conditions and at low pressures, the initial uptake coefficient of formic acid on CaCO 3 particles is measured to be 3 AE 1 Â 10 À3 and decreases as the surface saturates with adsorbed products. The maximum surface coverage of formic acid under dry conditions is determined to be (3 AE 1) Â 10 14 molecules cm À2. Under humidified conditions (RH 410%), adsorbed water on the surface of the carbonate particles participates in the surface reactivity of these particles, which results in the enhanced uptake kinetics and extent of reaction of this organic acid on CaCO 3 as well as opens up several new reaction pathways. These reaction pathways include: (i) the water-assisted dissociation of carbonic acid to CO 2 and H 2 O and (ii) the formation of calcium formate islands and crystallites, as evident by SEM images. The results presented here show that adsorbed water plays a potentially important role in the surface chemistry of gas-phase organic acids on calcium carbonate particles.
Physical Chemistry Chemical Physics, 2005
Calcium carbonate (CaCO3) is a reactive component of mineral dust aerosol as well as buildings, s... more Calcium carbonate (CaCO3) is a reactive component of mineral dust aerosol as well as buildings, statues and monuments. In this study, attenuated total reflection (ATR) and transmission Fourier transform infrared spectroscopy (FTIR) have been used to study the uptake of water, sulfur dioxide and nitric acid on CaCO3 particles at 296 K. Under atmospheric conditions, CaCO3 particles are terminated by a Ca(OH)(CO3H) surface layer. In the presence of water vapor between 5 and 95% relative humidity (RH), water molecularly adsorbs on the Ca(OH)(CO3H) surface resulting in the formation of an adsorbed thin water film. The adsorbed water film assists in the enhanced uptake of sulfur dioxide and nitric acid on CaCO3 in several ways. Under dry conditions (near 0% RH), sulfur dioxide and nitric acid react with the Ca(OH)(CO3H) surface to form adsorbed carbonic acid (H2CO3) along with sulfite and nitrate, respectively. Adsorbed carbonic acid is stable on the surface under vacuum conditions. Once the surface saturates with a carbonic acid capping layer, there is no additional uptake of gas-phase sulfur dioxide and nitric acid. However, upon adsorption of water, carbonic acid dissociates to form gaseous carbon dioxide and there is further uptake of sulfur dioxide and nitric acid. In addition, adsorbed water increases the mobility of the ions at the surface and enhances uptake of SO2 and HNO3. In the presence of adsorbed water, CaSO3 forms islands of a crystalline hydrate whereas Ca(NO3)2 forms a deliquescent layer or micropuddles. Thus adsorbed water plays an important and multi-faceted role in the uptake of pollutant gases on CaCO3.
Journal of Geophysical Research: Atmospheres, 2002
The heterogeneous uptake and oxidation of SO 2 on particle surfaces representative of mineral dus... more The heterogeneous uptake and oxidation of SO 2 on particle surfaces representative of mineral dusts found in the atmosphere have been investigated. These particles include metal oxides (e.g., hematite, corundum), calcite, and China loess. FT-IR spectroscopy was used to characterize surface-bound species following exposure to gaseous SO 2. It was found that SO 2 irreversibly adsorbs as sulfite (SO 3 2À) and/or bisulfite (HSO 3 À) on all particle surfaces with the exception of SiO 2. The adsorbed species can be oxidized to sulfate and/or bisulfate (SO 4 2À and/or HSO 4 À) upon exposure to ozone. Knudsen cell reactor studies were done to measure heterogeneous uptake coefficients for SO 2. Initial uptake coefficients, calculated using BET surface areas, g BET , are found to be lower than that found for water droplets. As shown here, the g BET value for China loess can be predicted from the reactivity of the single component oxide and carbonate particles along with the average composition of the dust sample, with each component weighted by its natural abundance in the sample.
The Journal of Contemporary Dental Practice, 2012
Aim • To find an alternative to popular orthodontic bonding agent composite resin and elimination... more Aim • To find an alternative to popular orthodontic bonding agent composite resin and elimination of acid etching. • To assess GC Fuji Ortho as an orthodontic bonding agent under different enamel conditions and evaluate the shear bond strength. • Enamel surfaces intentionally contaminated with saliva, conditioned enamel using Fuji dentin conditioner and conventional 37% phosphoric acid/60 seconds. • To evaluate and compare shear bond strength to a ‘gold standard’ composite bonding agent—Rely-a-Bond. Materials and methods The sample consisted of 50 human premolar teeth collected and stored in formalin. Out of 50 samples, 38 were upper premolars and 12 were lower second premolars. The total sample divide into 10 each. Stainless steel contour bracket with bondable mesh measured about 3.42 mm in length and 3.31 mm in width. Each tooth sample was embedded in a cylindrical acrylic block of polymethyl methacrylate (PMMN). The buccal surfaces of all the samples were polished with fluoride-f...
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Papers by Hashim Said Ali